The solution method is a method where raw material Si is melted in a graphite crucible to form a Si solution, C is dissolved out from the graphite crucible into the Si solution to form a Si—C solution which is then warmed and held, and a seed crystal is put into contact with the Si—C solution, thereby growing a SiC single crystal.
In the solution method, a temperature gradient in which the temperature decreases from the inside toward the solution surface and from the lower part to the upper part is maintained in the Si solution in a graphite crucible during the SiC single crystal growth. C dissolved out in a high-temperature part from the graphite crucible into the Si solution elevates following the convection of the Si—C solution and reaches a low-temperature part in the vicinity of the Si—C solution surface, as a result, C is supersaturated (hereinafter, sometimes referred to as a C-supersaturated part) in the vicinity of the Si—C solution surface.
Patent Document 1 discloses a method of producing a silicon single crystal by the Czochralski method. In the method disclosed in Patent Document 1, in order to make the in-plane distribution of the oxygen concentration in the produced single crystal uniform, in addition to melting raw material silicon by a resistance heating heater and warming/holding the silicon solution, the silicon solution is caused to undergo convection in a crucible by using a magnet.
Patent Document 2 discloses a production method of a SiC single crystal, where a Si—C solution is warmed and held using an induction heating coil. In the method disclosed in Patent Document 2, the temperature of the Si—C solution is controlled by controlling the current value of a high-frequency current flowed to the induction heating coil. Therefore, in the case of the production method disclosed in Patent Document 2, mainly natural convention is generated.